Compositions and Methods for Water Control and Strengthening Unconsolidated Formations

ABSTRACT

The present invention relates, in general, to subterranean fluids, and more particularly, to subterranean drilling fluids that may be useful for reducing the production of water from a portion of a subterranean formation and/or stabilizing an unconsolidated portion of a subterranean formation while drilling. In some embodiments, the present invention provides methods of reducing the flow of water from a portion of a subterranean formation that comprise contacting the portion of the subterranean formation with an organoaluminum compound, the organoaluminum compound being capable of forming a reaction product in the presence of water. The present invention also includes methods of drilling a well bore in a subterranean formation, methods of enhancing the stability of an unconsolidated portion of a subterranean formation, methods of stabilizing an unconsolidated portion of a subterranean formation, and drilling fluids.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional patent application of U.S. patentapplication Ser. No. 10/868,562, entitled “Compositions and Methods forWater Control and Strengthening Unconsolidated Formations,” filed onJun. 15, 2004, the entirety of which is incorporated herein byreference.

BACKGROUND

The present invention relates, in general, to subterranean fluids, andmore particularly, to subterranean drilling fluids that may be usefulfor reducing the production of water from a portion of a subterraneanformation and/or stabilizing an unconsolidated portion of a subterraneanformation while drilling.

The production of water with hydrocarbons from subterranean wellsgenerally is problematic and expensive. While hydrocarbon-producingwells are usually completed in hydrocarbon-bearing formations, suchformations may contain, or may be adjacent to, water-bearing sections.Generally, the term “water-bearing section” refers to any portion of asubterranean formation that may produce water, including ahydrocarbon-bearing section that has sufficiently high water contentsuch that water may be produced along with hydrocarbons. Water is highlymobile and easily may flow into the well bore by way of naturalfractures and/or high permeability streaks that may be present in theformation. Over the life of such wells, the ratio of water tohydrocarbons recovered may be undesirable in view of the cost ofproducing the water, separating it from the hydrocarbons, and disposingof it, which can represent a significant economic loss.

The production of water with desirable fluids may be addressed withconventional methods. For example, a treatment fluid including a resinmay be injected downhole to reduce the production of water withdesirable fluids. This method may include identifying a watered outsection, cleaning the filter cake with an acid, and injecting atreatment fluid including a resin into the watered out zone so as toreduce the production of water. This conventional approach generally isundesirable because it increases the cost, time, and labor associatedwith the well. Additionally, if the water-bearing section is notidentified accurately or sealed sufficiently, production of the desiredfluid, as opposed to the undesired water, may be reduced, which isundesirable.

Another potential problem in the production of hydrocarbons involvesunconsolidated portions of the subterranean formation, for example,unconsolidated sections of sand that may include water. Unconsolidatedportions of a subterranean formation include those that contain loosegrains of sand and those wherein the bonded grains of sand haveinsufficient bond strength to withstand forces generated by subterraneanoperations. Although unconsolidated sections of sand generally may berelatively easy to drill through while a positive differential pressureexists on the sand face, subsequent drilling operations may beproblematic. For example, removal of the drill string from the bore holemay reduce the pressure across the boundary between an unconsolidatedsection of sand and the well bore such that the bore hole may collapsewithin the section of unconsolidated sand. Consequently, sections ofunconsolidated sand that include a large amount of, or are saturatedwith, water can present prolonged difficulties during drilling andcasing operations that may lead to the loss of a section of a hole.

SUMMARY

The present invention relates, in general, to subterranean fluids, andmore particularly, to subterranean drilling fluids that may be usefulfor reducing the production of water from a portion of a subterraneanformation and/or stabilizing an unconsolidated portion of a subterraneanformation while drilling.

In some embodiments, the present invention provides a method of reducingthe flow of water from a portion of a subterranean formation. The methodcomprises contacting the portion of the subterranean formation with anorganoaluminum compound, the organoaluminum compound being capable offorming a reaction product in the presence of water.

In another embodiment, the present invention provides a method ofenhancing the stability of an unconsolidated portion of a subterraneanformation that comprises water. The method comprises contacting theunconsolidated portion of the subterranean formation with anorganoaluminum compound, the organoaluminum compound being capable ofreacting with the water in the unconsolidated portion to at leastpartially enhance the stability of the unconsolidated portion of thesubterranean formation.

In another embodiment, the present invention provides a method ofdrilling a well bore in a subterranean formation. The method comprisesproviding a drilling fluid that comprises an oil-based fluid and anorganoaluminum compound, and drilling the well bore using the drillingfluid.

In another embodiment, the present invention provides a method ofdrilling a well bore in a subterranean formation. The method comprisesproviding a first drilling fluid that comprises an oil-based fluid and afirst organoaluminum compound, the first organoaluminum compound beingcapable reacting with water to stabilize an unconsolidated section ofsand, wherein the unconsolidated section of sand includes the water. Themethod further comprises drilling the well bore using the first drillingfluid. The method further comprises providing a second drilling fluidthat comprises an oil-based fluid and a second organoaluminum compound,the second organoaluminum compound being capable of reacting with waterpresent in a water bearing section of the subterranean formation toreduce the flow of water therefrom. And the method further comprisesdrilling the well bore using the second drilling fluid.

In another embodiment, the present invention provides a method ofreducing the flow of water from a portion of a subterranean formation.The method comprises allowing an organoaluminum compound to react withwater present in the portion of the subterranean formation to form atleast one reaction product that at least partially blocks pore spaces inthe portion of the subterranean formation.

In another embodiment, the present invention provides a method ofstabilizing an unconsolidated portion of a subterranean formation thatcomprises water. The method comprises allowing an organoaluminumcompound to react with the water to form at least one reaction productthat acts to at least partially stabilize the unconsolidated portion ofthe subterranean formation.

In another embodiment, the present invention provides a drilling fluid.The drilling fluid comprises an oil-based fluid and an organoaluminumcompound, wherein the organoaluminum compound is capable of reactingwith water to form at least one reaction product.

The features and advantages of the present invention will be readilyapparent to those skilled in the art upon a reading of the detaileddescription that follows.

DETAILED DESCRIPTION

The present invention relates, in general, to subterranean fluids, andmore particularly, to subterranean drilling fluids that may be usefulfor reducing the production of water from a portion of a subterraneanformation and/or stabilizing an unconsolidated portion of a subterraneanformation while drilling.

The drilling fluids of the present invention generally comprise a basefluid and an organoaluminum compound that is capable of reacting withwater to form at least one reaction product. In certain embodiments, atleast a portion of the organoaluminum compounds in a drilling fluid mayleak off into the formation. If the subterranean formation includeswater, the organoaluminum compounds react with the water so as to format least one reaction product that blocks and/or reduces the volume ofthe pore spaces in the formation. Where a portion of the formationcomprises enough water to cause a large volume of the organoaluminumcompounds to react, the volume of the at least one reaction product maybe so high as to substantially block the production of water from thatportion of the formation. Other embodiments of the present inventionprovide drilling fluids that may be used in operations to stabilizeunconsolidated portions of a subterranean formation while drilling, forexample, to stabilize a section of unconsolidated sand that may includeundesirable water. In such embodiments, the selected organoaluminumcompound is capable of stabilizing an unconsolidated section of sand ina subterranean formation during drilling, e.g., by the at least onereaction product binding together some of the grains of sand in thesection.

Generally, the base fluid utilized in formulating the drilling fluids ofthe present invention may comprise any oil-based fluid suitable for usein drilling operations. Examples of suitable oil-based fluids include,but are not limited to, mineral oils, synthetic oils, esters, or anyother oil suitable for use in drilling operations. In one exemplaryembodiment, the base fluid comprises a refined hydrocarbon, such asdiesel oil or low toxicity mineral oil. Certain oil-based emulsions,such as an invert emulsion, may not be desirable because there may beundesirable interactions between the organoaluminum compounds and anaqueous phase in the emulsion. Thus, the drilling fluids of the presentinvention preferably should comprise a minimal amount of water that willnot negatively impact the organoaluminum compounds of the presentinvention.

Another component of the drilling fluid includes an organoaluminumcompound. Suitable organoaluminum compounds include organoaluminumcompounds that react with water to form at least one reaction product,which, inter alia, may act to block and/or reduce the pore volume of thesubterranean formation, and thereby reduce the flow of water from thesubterranean formation to the bore hole or well bore. Organoaluminumcompounds suitable for use in the present invention include long chainfatty acids, aluminum alcoholates, aluminum alkoxides, and aluminumbutoxides. In some embodiments, the aluminum alcoholate comprisesaluminum butoxides. Suitable examples includealuminum-bis-(2-butoxide)-ethylacetoacetate, andaluminum-(2-butoxide)-bis-(ethylacetoacetate). Other suitableorganoaluminum compounds include aluminum tri-isopropoxide, aluminumsec-butoxide di-isopropoxide, aluminum tri-isopropoxide octanol,aluminum ethylacetoacetate di-isopropoxide, aluminum ethylacetoacetatedi-octoxide, polyoxo aluminum octoate, aluminum carboxylate, andaluminum oleate. Some suitable long chain fatty acid organoaluminumcompounds include stearates. One suitable stearic acid is a carboxylicacid, wherein the hydrogen group is replaced by an aluminum group. Onesuch suitable carboxylic acid is aluminum oxystearate, which isrelatively stable in an oil-rich environment. Other suitableorganoaluminum compounds will be evident to one skilled in the art withthe benefit of this disclosure. Mixtures or combinations of differentorganoaluminum compounds also may be used in the compositions andmethods of the present invention.

The organoaluminum compounds of the present invention should react withwater to form at least one reaction product. Example reaction productsinclude precipitates and complexes (e.g., basic aluminum compounds andaluminum soaps) and combinations thereof, wherein the precipitates andcomplexes comprise aluminum hydroxide. In some embodiments, the at leastone reaction product includes aluminum hydroxide. For example, in onecertain embodiment, an aluminum alcoholate may react with water to format least one reaction product that includes aluminum hydroxide.

In selecting a suitable organoaluminum compound, one should be mindfulof the flash point of the selected organoaluminum compound. Inparticular, the hydrolysis of some organoaluminum compounds with watermay produce, among other things, an alcohol moiety that may release avolatile alcohol having a low flash point, which may become a hazard insome circumstances. For instance, aluminum tri-sec-butoxide has a flashpoint of about 26° C. Other organoaluminum compounds have higher flashpoints. For example, the hydrolysis ofaluminum-bis-(2-butoxide)-ethylacetoacetate andaluminum-(2-butoxide)-bis-(ethylacetoacetate) in mineral oil has a flashpoint of about 65° C. Flash points of some exemplary organoaluminumcompounds are given in Table 1.

TABLE 1 Flash Points of Some Organoaluminum Compounds ORGANOALUMINUMCOMPOUND FLASH POINT Aluminum tri-isopropoxide 17° C. Aluminumsec-butoxide di-isopropoxide 18° C. Aluminum tri-isopropoxide octanolcomplex 14° C. in white spirit Aluminum ethylacetoacetatedi-isopropoxide 35° C. Aluminum ethylacetoacetate di-octoxide 70° C.Aluminum carboxylate in high boiling solvent 68° C.

The concentration of the organoaluminum compound that should be includedin the drilling fluids of the present invention should be sufficient toprovide the desired functionality, for example, to reduce the productionof water and/or stabilize unconsolidated sections of sand. Generally,where desired to block and or reduce the volume of pore spaces in asubterranean formation to reduce the production of water, theconcentration of the organoaluminum compound in the drilling fluid willvary based on a number of factors, including the porosity of the rockformation and the dimension of the pores. For example, a formation withvery small pores (e.g., less than about 5 microns in diameter) willrequire less reaction products for effective blockage than a formationwith larger pores (e.g., up to about 50 microns in diameter).Irrespective of how the fluids of the present invention are used in adrilling operation, the drilling fluid, generally, should comprise asufficient amount of the organoaluminum compound to have an aluminumconcentration in the range of from about 0.005% to about 10% weight ofaluminum by volume of the drilling fluid (“w/v”). In other embodiments,the drilling fluid should comprise a sufficient amount of theorganoaluminum compound to have an aluminum concentration the range offrom about 0.05% to about 5% (w/v). In other embodiments, the drillingfluid should comprise a sufficient amount of the organoaluminum compoundto have an aluminum concentration in the range of from about 0.1% toabout 1% (w/v). In another embodiment, the drilling fluid shouldcomprise a sufficient amount of the organoaluminum compound to have analuminum concentration of about 0.5% (w/v).

Additional additives may be added to the drilling fluids of the presentinvention as deemed appropriate by one skilled in the art so long asthose additives are not incompatible with the chosen organoaluminumcompound. Examples of such additives include, but are not limited to,viscosifying agents (e.g., organophilic clay minerals), fluid lossagents (e.g., derivatives of asphalt or lignitic minerals), polaractivators (e.g., polyhydroxy compounds), desiccating or secondaryemulsifying agents (e.g., a tall oil), supplementary viscosifying orfluid loss agents required by the conditions of the drilling operation(e.g., block copolymers of styrene and ethylene/propylene), breakers,lost circulation materials (e.g., organic fibers and sized graphite),supplementary rheology additives based on fatty acid complexes, andcombinations thereof. The polar activator may be added to potentiate theactivity of the viscosifying agent such as organophilic clay. Thedesiccating or secondary emulsifying agent may be added to remove orimmobilize water that is picked up during the drilling operations.

The drilling fluids of the present invention may be formulated aslow-solids content drilling fluids or high-solids content drillingfluids, depending on the desired density of the drilling fluid. Oneembodiment of a low-solids content drilling fluid of the presentinvention comprises about 0.92 m³ of an oil such as a highly refinedlinear alkane, about 8.6 kg/m³ of a passive emulsifier such as a refinedtall oil fatty acid, about 51 kg/m³ of an organophilic clay such asbentonitic clay that has been treated with an amine, about 5.7 kg/m³ oflime (CaO), about 57 kg/m³ of an organophilic lignite or asphalt lignitesuch as a lignite that has been treated with an amine or powderedasphalt, about 100 litres/m³ of a fluid comprising about 62.8% (w/v)aluminum oxystearate and refined linear alkane oil, and about 30 kg/m³of a polar activator such as a polyhydroxy compound. In this embodiment,the low-solids content drilling fluid has an aluminum concentration ofabout 0.5 kg/m³.

An embodiment of a high-solids content drilling fluid of the presentinvention comprises about 0.75 m³ of an oil such as a highly refinedlinear alkane, about 8.6 kg/m³ of a passive emulsifier such as a refinedtall oil fatty acid, about 34 kg/m³ of an organophilic clay such as abentonitic clay that has been treated with an amine, about 40 kg/m³ ofan organophilic lignite or asphalt lignite such as a lignite that hasbeen treated with an amine or powdered asphalt, about 5.7 kg/m³ of lime,about 100 litres/m³ of a solution comprising about 62.8% (w/v) aluminumoxystearate in refined linear alkane oil, about 86 kg/m³ of 5 μmcarbonate, about 426 kg/m³ of 50 μm carbonate, and about 30 kg/m³ of apolar activator such as a polyhydroxy compound. In this embodiment, thehigh-solids content drilling fluid includes about 6.3 kg/m³ of aluminumoxystearate or an aluminum concentration of about 0.5 kg/m³.

In one embodiment, the present invention provides a method of drilling aportion of a well bore comprising the steps of providing a drillingfluid that comprises an organoaluminum compound and drilling the wellbore. Drilling the well bore may be accomplished by using drillingequipment, such as a drill string and a drill bit, along with thedrilling fluid. Drilling operations may include any suitable techniquefor forming a well bore that penetrates a subterranean formation.Examples of suitable techniques for forming a well bore may include, butare not limited to, rotary drilling and cable-tool drilling. Othertechniques for forming a well bore may be used, but generally to alesser extent. Rotary drilling operations typically involve attaching adrill bit on a lower end of a drill string to form a drilling tool androtating the drill bit along with the drill string into a subterraneanformation to create a well bore through which subsurface formationfluids may be produced. As the drill bit penetrates the subterraneanformation, additional joints of pipe may be coupled to the drill string.In another method of drilling, coiled tubing may be used instead ofjointed pipe and the drill bit may be rotated using a downhole motor.

Drilling fluids of the present invention also may provide a method ofstrengthening an unconsolidated portion of a subterranean formationduring drilling. For example, a drilling fluid that comprises anorganoaluminum compound may be used during drilling to strengthen anunconsolidated section of sand that includes water. In one embodiment,the organoaluminum compound in the drilling fluid may react with waterin the unconsolidated portion to form at least one reaction product thatat least partially stabilizes the unconsolidated portion. For example,the reaction of the organoaluminum compound in the treatment fluid withwater in an unconsolidated section of sand may bind together a portionof the unconsolidated section of sand, e.g., by binding together thegrains of sand in the unconsolidated section. Following the reaction ofan organoaluminum compound with water, the binding strength of thenear-well bore region may be enhanced sufficiently so as to reduce thepossibility of a well bore collapse near the unconsolidated portion ofthe subterranean formation, during, for example, casing.

It should be readily apparent to one skilled in the art with the benefitof this disclosure that the organoaluminum compounds of the presentinvention may be used in applications other than drilling. The methodsand drilling fluids of the present invention may be useful in additionalsubterranean applications, for example, where it is desirable to reduceor prevent the inflow of water and/or stabilize unconsolidated portionsof a formation. In one embodiment, the organoaluminum compound may bedelivered down hole via a wireline tool. The wireline tool may include areservoir or storage tank capable of transferring an organoaluminumcompound into the well bore. In another embodiment, the drill string maybe removed from the bore hole, and the aluminum compound may be injecteddirectly downhole into the vicinity of the water-bearing section orunconsolidated portion of a subterranean formation. For example, thecompounds and fluids of the present invention may be injected into theannulus flow of the drill string. In another embodiment, resins may beincluded with organoaluminum compounds to seal water-bearing sections orreduce the flow of water from water-bearing sections.

In still another embodiment, the compositions and fluids of the presentinvention may include servicing or completion fluids. A servicing orcompletion fluid may be used, for example, during an operation tostabilize an unconsolidated section of sand following penetration ofthat section by the drill bit. In one embodiment, the compositions andfluids of the present invention may be delivered into, or substitutedfor, the annulus fluid of the drilling system. Alternatively, the drillstring may be removed and the fluids and compositions of the presentinvention may be injected downhole into well bore.

In some embodiments, the present invention provides a method of reducingthe flow of water from a portion of a subterranean formation. The methodcomprises contacting the portion of the subterranean formation with anorganoaluminum compound, the organoaluminum compound being capable offorming a reaction product in the presence of water. In someembodiments, the method may further comprise allowing the organoaluminumcompound to react with the water present in the subterranean formationso as to form the at least one reaction product.

In another embodiment, the present invention provides a method ofenhancing the stability of an unconsolidated portion of a subterraneanformation that comprises water. The method comprises contacting theunconsolidated portion of the subterranean formation with anorganoaluminum compound, the organoaluminum compound being capable ofreacting with the water in the unconsolidated portion to at leastpartially enhance the stability of the unconsolidated portion of thesubterranean formation. In some embodiments, the method may furthercomprise allowing the organoaluminum compound to react with the water inthe unconsolidated portion of the subterranean formation to at leastpartially enhance the stability of the unconsolidated portion of thesubterranean formation.

In another embodiment, the present invention provides a method ofdrilling a well bore in a subterranean formation. The method comprisesproviding a drilling fluid that comprises an oil-based fluid and anorganoaluminum compound, and drilling the well bore using the drillingfluid.

In another embodiment, the present invention provides a method ofdrilling a well bore in a subterranean formation. The method comprisesproviding a first drilling fluid that comprises an oil-based fluid and afirst organoaluminum compound, the first organoaluminum compound beingcapable reacting with water to stabilize an unconsolidated section ofsand, wherein the unconsolidated section of sand includes the water. Themethod further comprises drilling the well bore using the first drillingfluid. The method further comprises providing a second drilling fluidthat comprises an oil-based fluid and a second organoaluminum compound,the second organoaluminum compound being capable of reacting with waterpresent in a water bearing section of the subterranean formation toreduce the flow of water therefrom. And the method further comprisesdrilling the well bore using the second drilling fluid.

In another embodiment, the present invention provides a method ofreducing the flow of water from a portion of a subterranean formation.The method comprises allowing an organoaluminum compound to react withwater present in the portion of the subterranean formation to form atleast one reaction product that at least partially blocks pore spaces inthe portion of the subterranean formation.

In another embodiment, the present invention provides a method ofstabilizing an unconsolidated portion of a subterranean formation thatcomprises water. The method comprises allowing an organoaluminumcompound to react with the water to form at least one reaction productthat acts to at least partially stabilize the unconsolidated portion ofthe subterranean formation.

In another embodiment, the present invention provides a drilling fluid.The drilling fluid comprises an oil-based fluid and an organoaluminumcompound, wherein the organoaluminum compound is capable of reactingwith water to form at least one reaction product.

To facilitate a better understanding of the present invention, thefollowing examples of certain embodiments are given. In no way shouldthe following examples be read to limit, or to define, the scope of theinvention.

EXAMPLES Example 1

A steel cell was packed with Ballotini glass spheres having diametersbetween 4 and 45 microns to simulate a fairly permeable formation havinga permeability of about 800 mD. The steel cell was connected into a flowloop that allowed a fluid to be flowed through the steel cell and forthe flow rate and differential pressures across the cell to be measured.An aluminum oxystearate fluid was initially prepared as a fluid of a lowtoxicity oil such as “CLAIRSOL 370” (available from Petrochem CarlessLtd., Surrey England) having a final concentration of about 5% (w/w)aluminum. A 10% aluminum stearate solution (v/v, 0.5% concentration ofaluminum) was prepared by diluting the aluminum stearate solution withCLAIRSOL 370 oil.

Water was flowed through the steel cell containing the glass spheres ata constant rate of 72 ml/min at 0.6 bar. The “production direction” wasdefined to be the direction of the water flow. Next, 15 ml of the 10%aluminum oxystearate solution (0.5% final concentration of aluminum) wasinjected into the cell in a direction opposite the production direction.Subsequently, 15 ml of the CLAIRSOL 370 oil was injected into the cellin a direction opposite the production direction. The cell was thensealed and static aged at about 60° C. for about 56 hours. The agingstep was performed to simulate the condition that the field injectedfiltrate would remain in place for several hours—if not days—beforeproduction of fluid would be attempted.

After the aging process, water was flowed in the production direction ata constant differential pressure for five minutes and the flow rate wasmeasured. The differential pressure was increased (or decreased)according to the first column of Table 2 and a flow rate was obtainedfor each differential pressure measurement. Table 2 summarizes theresults of this example.

TABLE 2 Flow rate as a function of differential pressure. DIFFERENTIALPRESSURE (bar) FLOW RATE (ml/min) 0 0 0.1 0 0.2 0 0.3 0 0.4 3.3 0.5 4.80.6 7.6 1.0 16.5 1.0 20 1.0 21 0.6 10.6

As shown in Table 2, aluminum oxystearates appear to reduce the flowrate of water through the test cell. The flow rate of the water at adifferential pressure of 0.6 bar was between 7.6 and 10.6 ml/min, whichis about 10-15% of the flow rate before the test, or a reduction in flowrate of about 85-90%. Moreover, it is possible that the reduction inflow rate by the aluminum oxystearates may be enhanced in a medium oflower permeability because the pores surrounding the smaller particlesshould be easier to block. Moreover, some of the glass balls hadconsolidated after the test.

Example 2

Additional tests were performed to determine the effect of introducingCLAIRSOL 370 oil, by itself, into a steel cell. A steel cell was packedwith Ballotini glass spheres having diameters between 4 and 45 micronsto simulate a fairly permeable formation having a permeability of about800 mD. The steel cell was connected into a flow loop that allowed afluid to be flowed through the steel cell and for the flow rate anddifferential pressures across the cell to be measured.

Water was flowed through the steel cell containing the glass spheres.The differential pressure was increased and an associated flow rate wasobtained for each differential pressure. The “production direction” wasdefined to be the direction of the water flow. The measured flow ratesand associated differential pressures are provided below in Table 3.

TABLE 3 Flow rate as a function of differential pressure. FLOW RATE(ML/MIN) DIFFERENTIAL After 17 PRESSURE (BAR) Initial After 16 hourshours 0.1 bar 10 14 12 0.2 bar 24 28 26 0.3 bar 37 43 43 0.4 bar 52 5960 0.5 bar 61 74 74 0.6 bar 81 89 88

Next, 19 ml of CLAIRSOL 370 oil was injected into the cell in adirection opposite the production direction to determine the effect ofintroducing oil into the steel cell. The injection was allowed toproceed under gravitational flow and 19 ml of the oil flowed into thecell in 80 minutes. Accordingly, approximately 30% of the water in thesteel cell was displaced by the oil. Furthermore, 4 ml of oil camethrough the steel cell, which indicates that the oil had channeled inthe cell. Next, water was flowed through the cell in the productiondirection, the differential pressure was increased, and an associatedflow rate was obtained for each differential pressure. The results ofthis test are provided below in Table 4.

TABLE 4 Flow rate as a function of differential pressure afterintroducing oil. FLOW RATE DIFFERENTIAL PRESSURE (BAR) (ML/MIN) 0.1 bar10 0.2 bar 21 0.3 bar 32 0.4 bar 44 0.5 bar 55 0.6 bar 66

Accordingly, injection of the CLAIRSOL 370 oil, by itself, reduces theflow rate through the steel cell by about 20%. For example, the flowrate measurements for a differential pressure of 0.6 bar afterintroduction of the oil were about 20% lower than the measured initialflow rate.

Example 3

Example 3 investigates at least some of the effects of aluminumalcoholates on the water flow rate through a test cell containingBallotini glass balls. An oil fluid of a mixture ofaluminum-bis-(2-butoxide)-ethylacetoacetate andaluminum-(2-butoxide)-bis-(ethylacetoacetate), with an aluminum contentof 6.2% was chosen for study. The test aluminum alcoholate solution wasa 10% solution of the aluminum alcoholate oil solution in a CLAIRSOL 370oil solution resulting in a final aluminum concentration of about 0.62%.

The same apparatus and experimental steps of Example 1 were used in thisexample. The water flow rate before the test was adjusted to be about 68ml/min at 0.6 bar. The “production direction” was defined to be thedirection of water flow. Then 15 ml of the test organoaluminum solution(final aluminum concentration of about 0.6%) was injected into the cellin a direction opposite to the production direction, followed by aninjection of 15 ml of CLAIRSOL 370 in the production direction.Following the aging step (baking at 60° C. for 56 hours), water wasagain flowed in the production direction.

Water was flowed at a constant differential pressure through the testcell for five minutes and the flow rate was measured. The differentialpressure increased according to the first column of Table 5, and a flowrate was obtained for each differential pressure measurement. Table 5summarizes the results of this example.

TABLE 5 Flow rate after treatment with aluminum alcoholate. DIFFERENTIALPRESSURE (bar) FLOW RATE (ml/min) 0.1 3.8 0.2 8.2 0.3 16 0.4 26 0.5 340.6 38

The results of Table 5 illustrate that the water flow rate followinginjection of aluminum alcoholate was reduced by about 45%. However, asillustrated by Example 2, injection of CLAIRSOL 370 alone may havereduce the flow rate of water by about 20%. The results shown in Table 5illustrate that aluminum alcoholates may reduce the flow rate of waterthrough the Ballotini bed. Additionally, the loose Ballotini balls hadconsolidated following the treatment with aluminum alcoholate. Theportion of the bed that had been invaded by the solution was no longerloose, but formed a large clump of consolidated Ballotini which firmlyfilled the volume section of the steel cell. Significant effort wasrequired to extract the Ballotini spheres from the cell. Specifically,the unconfined crushing strength of the treated Ballotini had increasedfrom 0 psi to more than 50 psi.

Therefore, the present invention is well adapted to carry out theobjects and attain the ends and advantages mentioned as well as thosewhich are inherent therein. While numerous changes may be made by thoseskilled in the art, such changes are encompassed within the spirit ofthis invention as defined by the appended claims.

1. A method of drilling a well bore in a subterranean formation,comprising: providing a drilling fluid that comprises an oil-based fluidand an organoaluminum compound; and drilling the well bore using thedrilling fluid.
 2. The method of claim 1 wherein the organoaluminumcompound reacts with water present in the subterranean formation toproduce at least one reaction product that reduces the flow of waterfrom the subterranean formation.
 3. The method of claim 1 wherein theorganoaluminum compound reacts with water present in an unconsolidatedportion of the subterranean formation to produce at least one reactionproduct that at least partially stabilizes the unconsolidated portion.4. A method of drilling a well bore in a subterranean formation,comprising: providing a first drilling fluid that comprises an oil-basedfluid and a first organoaluminum compound, the first organoaluminumcompound being capable reacting with water to stabilize anunconsolidated section of sand, wherein the unconsolidated section ofsand includes the water; drilling the well bore using the first drillingfluid; providing a second drilling fluid that comprises an oil-basedfluid and a second organoaluminum compound, the second organoaluminumcompound being capable of reacting with water present in a water-bearingsection of the subterranean formation to reduce the flow of watertherefrom; and drilling the well bore using the second drilling fluid.5. The method of claim 4 wherein the first organoaluminum compoundcomprises at least one organoaluminum compound selected from the groupconsisting of: an aluminum alkoxide, an aluminum butoxide, an aluminumtri-isopropoxide, an aluminum sec-butoxide di-isopropoxide, an aluminumtri-isoproxide octanol, an aluminum ethylacetoacetate di-isopropoxide,an aluminum ethylacetoacetate di-octoxide, and any combination thereof.6. The method of claim 4 wherein the second organoaluminum compoundcomprises an aluminum oxystearate.
 7. A drilling fluid comprising: anoil-based fluid; and an organoaluminum compound, wherein theorganoaluminum compound is capable of reacting with water to form atleast one reaction product.
 8. The drilling fluid of claim 7 wherein theorganoaluminum compound comprises at least one organoaluminum compoundselected from the group consisting of: an aluminum alkoxide, an aluminumbutoxide, an aluminum tri-isopropoxide, an aluminum sec-butoxidedi-isopropoxide, an aluminum tri-isoproxide octanol, an aluminumethylacetoacetate di-isopropoxide, an aluminum ethylacetoacetatedi-octoxide, and any combination thereof.
 9. The drilling fluid of claim8 wherein the aluminum alcoholate comprises an aluminum butoxide. 10.The drilling fluid of claim 7 wherein the organoaluminum compoundcomprises a stearate.
 11. The drilling fluid of claim 10 wherein thestearate comprises an aluminum oxystearate.
 12. The drilling fluid ofclaim 10 wherein the organoaluminum compound comprises at least oneorganoaluminum compound selected from the group consisting of: analuminum-bis-(2-butoxide)-ethylacetoacetate, an aluminum-(2butoxide)-bis-(ethylacetoacetate), and any mixture thereof.
 13. Thedrilling fluid of claim 7 wherein the organoaluminum compound comprisesat least one organoaluminum compound selected from the group consistingof: an aluminum oxystearate, an aluminum alcoholate, an aluminumalkoxide, an aluminum butoxide, a long chain fatty acid, an aluminumtri-isopropoxide, an aluminum sec-butoxide di-isopropoxide, an aluminumtri-isoproxide octanol, an aluminum ethylacetoacetate di-isopropoxide,an aluminum ethylacetoacetate di-octoxide, a polyoxo aluminum octoate,an aluminum carboxylate, an aluminum oleate, and any combinationthereof.
 14. The method of claim 7 wherein the oil-based fluid comprisesa mineral oil, a synthetic oil, an ester, or a combination thereof. 15.The method of claim 7 wherein the oil-based fluid comprises a refinedhydrocarbon.
 16. The drilling fluid of claim 7 wherein the drillingfluid comprises a sufficient amount of the organoaluminum compound tohave an aluminum concentration in the range of from about 0.005% toabout 10% weight of aluminum by volume of the drilling fluid.
 17. Thedrilling fluid of claim 7 wherein the drilling fluid comprises asufficient amount of the organoaluminum compound to have an aluminumconcentration in the range of from about 0.05% to about 5% weight ofaluminum by volume of the drilling fluid.
 18. The drilling fluid ofclaim 7 wherein the drilling fluid comprises a sufficient amount of theorganoaluminum compound to have an aluminum concentration in the rangeof from about 0.1% to about 1% weight of aluminum by volume of thedrilling fluid.
 19. The drilling fluid of claim 7 wherein the drillingfluid comprises a sufficient amount of the organoaluminum compound tohave an aluminum concentration of about 0.5% weight of aluminum byvolume of the drilling fluid.
 20. The drilling fluid of claim 7 whereinthe drilling fluid further comprises a viscosifying agent, a fluid lossagent, a polar activator, a desiccating agent, a supplementary viscosityagent, a fluid loss agent, a breaker, a lost circulation material, or acombination thereof.